INSECTS
tubular part, the small intestine (SInt), and of a great terminal receptacle, the rectum (Rect), filled with a mass of soft orange-colored matter. In the fully-matured insect (C), after it has escaped from the cocoon, still further
Fig. 164. Transformation in the form of the alimentary canal of the tent caterpillar from the larva to the adult moth
A, alimentary canal of the caterpillar. B, the same of the pupa. C, the same of the moth
Cr, crop; Int, intestine; Mal, Malpighian tubules (not shown full length); Oe, oesophagus; Rect, rectum; SInt, small intestine; Vent, ventriculus
alterations have taken place. The crop sac (Cr) is now greatly distended into a spherical vesicle tensely filled with gas—air, probably, that the moth has swallowed, perhaps to aid it in breaking the pupal shell, for there are sometimes small bubbles also in the tubular oesophagus.
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